Central base coils for deep transcranial magnetic stimulation

ABSTRACT

A transcranial magnetic stimulation coil which is location-specific for medial brain regions or lateral brain regions is designed with multiple spaced apart stimulating elements having current flow in a first direction, and multiple return elements having current flow in a second direction which is opposite the first direction. The multiple stimulating elements are distributed around a central axis of the coil.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of U.S. applicationSer. No. 13/772,442, filed on Feb. 21, 2013, now U.S. Pat. No.9,254,394, issued on Feb. 9, 2016.

FIELD OF THE INVENTION

The present invention relates to a family of deep transcranial magneticstimulation (TMS) coils for stimulating medial or lateral brain regions.

BACKGROUND OF THE INVENTION

Transcranial magnetic stimulation (TMS) is a noninvasive technique usedto apply brief magnetic pulses to the brain, or to other human organs,and to thereby activate neuronal structures. The pulses are administeredby passing high currents by a stimulator through an electromagnetic coilexternally placed upon the patient (for example, placed on the scalp forbrain treatment), inducing electrical currents in the underlying tissue,thereby producing a localized axonal depolarization. This technique hasbecome a major tool in central nervous system research, as well as apotentially promising treatment option for various neurobehavioral andneurological disorders.

Most known TMS coils stimulate superficial brain regions in the braincortex, but the rate of decay of the induced magnetic and electric fieldas a function of distance from the coil is high. Hence the efficacy ofaffecting deeper neuronal structures is low. Stimulating deeper neuronalstructures may be feasible if the intensity of the induced field isgreatly increased. Yet operation at such increased intensity mayincrease the risk for seizures and for physiological damage to thetissue.

A method for deep brain TMS with minimal stimulation of superficialregions is disclosed in U.S. Pat. No. 7,407,478, wherein deep brainstimulation is made possible while minimizing side effects. The devicedescribed therein includes a base and an extension portion, the basehaving individual windings for individual paths of current flow, and theextension portion designed so as to minimize unwanted stimulation ofother regions of the brain.

However, there is a need for more specifically designed coils, which cantarget particular areas of the brain including deep neuronal structureswith minimal effect on other brain regions. Examples of specific brainregions that may be desired to be stimulated are medial brain regionsincluding the anterior cingulate cortex, medial prefrontal cortex,medial motor cortex, the supplementary motor area (SMA), the premotorarea (PMA), the posterior cingulate cortex, and regions in thepreconeus. Other examples may include lateral brain regions such as thelateral prefrontal cortex, the insula, the entorhinal cortex, temporalcortex regions and the fusiform face area (FFA).

Thus, there is a need for specifically designed coils for deep TMS whichare location-specific for medial brain regions or lateral brain regions.The coils must induce the desired distribution of the electric field inthe brain, and simultaneously induce electric field intensity in therelevant brain tissue which will be feasible for neuronal stimulationwith available TMS stimulators for most of the population. Thestimulation intensity is routinely calibrated individually for eachsubject based on his or her motor threshold. Hence the coil efficiencymust guarantee that the motor threshold and stimulation intensity formost of the relevant population is within an acceptable range withrespect to available stimulators power outputs.

The coils design must be efficient with respect to energy consumption,coil heating rate, compact size and ease of operation.

SUMMARY OF THE INVENTION

There is provided, in accordance with one embodiment of the presentinvention, a coil for transcranial magnetic stimulation. The coilincludes a base portion having a central axis defining a base portionright side on a right side of the central axis and a base portion leftside on a left side of the central axis, multiple right side stimulatingelements positioned in the base portion right side, configured to carryelectrical current in a first direction, multiple left side stimulatingelements positioned in the base portion left side, configured to carryelectrical current in the same first direction. The coil furtherincludes a return portion having multiple right side return elements,wherein each of the right side return elements corresponds to one of themultiple right side stimulating elements, and wherein each of themultiple right side return elements is configured to carry electricalcurrent in a second direction which is opposite the first direction, andmultiple left side return elements, wherein each of the left side returnelements corresponds to one of the multiple left side stimulatingelements, and wherein each of the multiple left side return elements isconfigured to carry electrical current in the second direction, whereinthe return portion is spaced a distance away from said base portion.

In embodiments of the present invention, the base portion iscomplementary to the human head or head portion, or to another bodyorgan. The base has a flexibility that allows it to conform to therelevant body organ (such as the human head or head portion).

The base includes individual elements carrying electric current in oneor more common directions, referred to herein as a “main direction.” Inthis main direction, the main physiologic effect (such as neuronalstimulation) is induced in the body organ. The elements are not densetogether at a narrow segment, but are rather distributed at variouslocations around the body organ. In some embodiments the individualelements are evenly distributed across the base. In other embodimentssome or all the elements may be grouped in two or more groups withcertain distances between the groups. The spacing between adjacentelements may be uniform, variable, periodic or other. In embodimentswhere some or all the elements are grouped in groups, the spacingbetween adjacent groups or between a group and an adjacent element, andthe breadth of each group, may be uniform across the base, variable,periodic or other. Any combination or arrangement of elements isincluded within the scope of the invention, with a particular featurebeing that the elements are not crowded together in a narrow segment.

The individual elements in the base carrying current in the maindirection are all or mostly tangential to the relevant body organ (suchas a portion of a human skull), at all or a substantial part of theirpath. In order to optimize the efficacy of activation in deeper brainregions, it is desirable to minimize the non-tangential components ofthe induced electric field. Since the induced electric field orientationis in general parallel to the orientation of the elements carryingalternating currents, it is desirable to minimize the portions of coilelements which are non-tangential to the body organ (such as a humanskull), especially in the base and its vicinity.

Coil elements carrying electric current in a direction opposite to theone or more main directions, are placed remote from the base. Theseelements are referred to herein as “return elements.” In someembodiments, the return elements are located adjacent to other bodyorgans or other portions of a body organ (such as other head regions),relative to the base. These return elements are termed “contactingreturn elements.” In other embodiments, the return elements are locatedat a certain distance from the body and are not configured to contactthe body. These return elements are termed “protruding return elements.”In some embodiments, some of the return elements are contacting and someof them are protruding.

Return elements may be located on more than one side of the base. Insome embodiments, the coil includes return elements on two sides of thebase. In other embodiments, the coil includes return elements on threeor more sides of the base. As an example, a certain embodiment mayinclude a central medial base located over a human medial cortex, andtwo groupings of return elements located to the left and to the right ofthe central base. In some embodiments, these return elements arecontacting and adjacent to lateral cortical regions. In otherembodiments these return elements are protruding and located at adistance from any brain region. In yet other embodiments, some of thereturn elements are contacting and some are protruding. In someembodiments all the return elements on one side of the base—i.e.left—are contacting, while all the return elements on the other side areprotruding. In yet other embodiments, each side of the base—i.e. leftand right—includes both contacting and protruding return elements. Inyet other embodiments, one side of the base—i.e. right—includes bothcontacting and protruding return elements, while the other side includesonly contacting or only protruding return elements.

The definition of the base relates to the functional elements of thecoil carrying electric currents. However, there is no limitationregarding other elements of the device, such as mechanical components,cases and covers. Thus, certain elements of the base may be encased in acase containing additional coil elements such as return elements andother elements. As an example, in a central base coil with a base placedover a medial cortex region, and having two lateral return portions tothe left and to the right of the base, the base may include twogroupings—left and right—of elements leading current in a maindirection. In some embodiments the left group elements may be encased ina case together with the left return elements, and similarly for theright group in some embodiments. Hence mechanically the coil may becomprised of two portions—left and right—each of them having bothcentral base elements and return elements. Yet, functionally the coil iscomprised of a central base including elements leading currents in amain direction, and two return portions to the left and right of thebase, including return elements leading currents in an oppositedirection. Thus, the definitions of stimulating elements, returnelements and connecting elements are based on the functionality of theseelements or portions thereof.

The coil must induce the desired distribution of the electric field inthe brain, and simultaneously induce an electric field intensity in therelevant brain tissue which is high enough to induce neuronalstimulation.

Several features of the coil are important in order to achieve the abovegoals. These include:

1. Arrangement of the base portion elements. This arrangement must beoptimized for each coil design and each specific goal. An interplaybetween two competing ideals may take place: Better depth penetrationprofile, namely higher relative electric field in the deeper targetbrain region compared to superficial region, on one hand, and higherabsolute electric field intensity in the target brain region on theother hand. As a non-limiting example, suppose a base portion containstwo groups of elements with a certain distance d between them.Increasing d will improve the depth penetration profile but may reducethe absolute field intensity in the target brain region. The intensitymust be such that it will enable induction of the desired physiologicaleffect in the target neural structures in the majority of the populationwith stimulators available in the market. Hence the distance d—as wellas other configuration parameters—must be optimized for each coildesign.

2. Location of the return portions relative to the base portion. Thedistance between the portions must be optimized for each design: Tooshort a distance will lead to reduction of the total induced electricfield in the target brain region, due to the effect of the returnelements. Too long a distance will require long connecting coil elementsand their effect must be taken into account. Furthermore, the coil sizemust be optimized for easy location, navigation and placement over thehead.

3. Location of the return portions relative to the brain. The returnelements affect closer brain regions. The location of the returnportions must consider their effect on any brain structure and thedesign must lead to minimal undesired side effects such as motoractivation or pain.

4. The type of the return elements. Return elements may be eithercontacting or protruding as defined above. The ratio between contactingand protruding return elements is very important in various aspects andmust be optimized for each specific coil design. In general, protrudingelements induce electrostatic charge accumulation on the brain surface.This leads to reduction in the absolute electric field induced in thetarget brain regions, and also reduction in the relative intensity ofthe electric field in deeper brain regions compared to superficialregions. On the other hand, contacting elements may increase the effectin adjacent brain regions. Hence a delicate optimization must beperformed in each case.

5. The distance of protruding return elements from the head, in coilscontaining protruding return elements. Longer distance reduces thedirect effect of the return elements on the brain, but increases thecharge accumulation due to the presence of longer non-tangential coilelements which are connected to the return elements and move them awayfrom the head. A delicate optimization must be performed in each case toaccount for this effect.

6. The overall coil inductance. The number, length, configuration andpacking parameters of the coil windings must be planned to lead to coilinductance in the desired range. Usually the desired range for TMS coilsinductance is between 15 and 30 microHenri. Too high inductance mayreduce coil efficacy, increase pulse width and is often associated withincreased coil resistance, energy consumption and coil heating. Toosmall inductance may lead to fast rate of change of the electric currentwhich may damage stimulator components.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of the present invention, suitable methods andmaterials are described below. In case of conflict, the patentspecification, including definitions, will control. In addition, thematerials, methods, and examples are illustrative only and not intendedto be limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and further advantages of the present invention may be betterunderstood by referring to the following description in conjunction withthe accompanying drawings in which:

FIG. 1 is a schematic illustration showing principles of stimulation forcentral base coils, in accordance with embodiments of the presentinvention;

FIGS. 2A-2F are schematic illustrations of a base portion of the centralbase coils shown schematically in FIG. 1 in accordance with embodimentsof the present invention;

FIG. 3 is an illustration of a return portion of the central base coilsshown schematically in FIG. 1, in accordance with embodiments of thepresent invention;

FIG. 4 is an illustration of anatomical sections of a head;

FIG. 5 is a perspective illustration of a coil, which is an example of acentral base coil as shown schematically in FIG. 1, in accordance withembodiments of the present invention;

FIG. 6 is a perspective illustration of a coil, which is an example of acentral base coil as shown schematically in FIG. 1, in accordance withembodiments of the present invention;

FIG. 7 is a perspective illustration of a coil, which is an example of acentral base coil as shown schematically in FIG. 1, in accordance withembodiments of the present invention;

FIGS. 8A-8B are perspective illustrations of a coil, which is an exampleof a central base coil as shown schematically in FIG. 1, in accordancewith embodiments of the present invention;

FIG. 9 is a perspective illustration of a coil, which is an example of acentral base coil as shown schematically in FIG. 1, in accordance withembodiments of the present invention;

FIG. 10 is a perspective illustration of a coil, which is an example ofa central base coil as shown schematically in FIG. 1, in accordance withembodiments of the present invention;

FIG. 11 is a perspective illustration of a coil, which is an example ofa central base coil as shown schematically in FIG. 1, in accordance withembodiments of the present invention;

FIG. 12 is a perspective illustration of a coil, which is an example ofa central base coil as shown schematically in FIG. 1, in accordance withembodiments of the present invention;

FIGS. 13A and 13B are perspective illustrations of a coil, shown off andon a head, respectively, which is an example of a central base coil asshown schematically in FIG. 1, in accordance with embodiments of thepresent invention;

FIG. 14 is a perspective illustration of a coil, which is an example ofa central base coil as shown schematically in FIG. 1, in accordance withembodiments of the present invention;

FIG. 15 is a perspective illustration of a coil, which is an example ofa central base coil as shown schematically in FIG. 1, in accordance withembodiments of the present invention;

FIG. 16 is a perspective illustration of a coil, which is an example ofa central base coil as shown schematically in FIG. 1, in accordance withembodiments of the present invention;

FIGS. 17A-C are perspective illustrations of a coil, which is an exampleof a central base coil as shown schematically in FIG. 1, in accordancewith embodiments of the present invention;

FIG. 18 is an illustration of electric field distribution maps of thecoil of FIG. 5 as measured in a human head phantom model;

FIG. 19 is an illustration of electric field distribution maps of thecoil of FIG. 6 as measured in a human head phantom model;

FIG. 20 is an illustration of electric field distribution maps of thecoil of FIG. 7 as measured in a human head phantom model;

FIG. 21 is an illustration of electric field distribution maps of thecoil of FIG. 8 as measured in a human head phantom model;

FIG. 22 is an illustration of electric field distribution maps of thecoil of FIG. 9 as measured in a human head phantom model;

FIG. 23 is an illustration of electric field distribution maps of thecoil of FIG. 10 as measured in a human head phantom model;

FIG. 24 is an illustration of electric field distribution maps of thecoil of FIG. 11 as measured in a human head phantom model;

FIG. 25 is an illustration of electric field distribution maps of thecoil of FIG. 12 as measured in a human head phantom model;

FIG. 26 is an illustration of electric field distribution maps of thecoil of FIGS. 13A and 13B as measured in a human head phantom model;

FIG. 27 is an illustration of electric field distribution maps of thecoil of FIG. 14 as measured in a human head phantom model;

FIG. 28 is an illustration of electric field distribution maps of thecoil of 15 as measured in a human head phantom model;

FIG. 29 is an illustration of electric field distribution maps of thecoil of FIG. 16 as measured in a human head phantom model; and

FIG. 30 is an illustration of electric field distribution maps of thecoil of FIG. 17 as measured in a human head phantom model.

It will be appreciated that for simplicity and clarity of illustration,elements shown in the drawings have not necessarily been drawnaccurately or to scale. For example, the dimensions of some of theelements may be exaggerated relative to other elements for clarity orseveral physical components may be included in one functional block orelement. Further, where considered appropriate, reference numerals maybe repeated among the drawings to indicate corresponding or analogouselements. Moreover, some of the blocks depicted in the drawings may becombined into a single function.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the presentinvention. It will be understood by those of ordinary skill in the artthat the present invention may be practiced without these specificdetails. In other instances, well-known methods, procedures, componentsand structures may not have been described in detail so as not toobscure the present invention.

The present invention is directed to central base coils for deep TMS andmethods of use thereof. The principles and operation of systems andmethods according to the present invention may be better understood withreference to the drawings and accompanying descriptions.

Before explaining at least one embodiment of the present invention indetail, it is to be understood that the invention is not limited in itsapplication to the details of construction and the arrangement of thecomponents set forth in the following description or illustrated in thedrawings. The invention is capable of other embodiments or of beingpracticed or carried out in various ways. Also, it is to be understoodthat the phraseology and terminology employed herein are for the purposeof description and should not be regarded as limiting.

Each of the examples below is a coil construction designed uniquely foreffective activation of specific deep brain regions. Each of these coilswas constructed after a complex development process including computersimulation of the electric field distribution induced in the brain byvarious coil configurations, building and experimenting with variousprototypes, electric field measurements in a phantom head model filledwith saline solution at physiologic concentration, and iterationsbetween computer simulations and phantom brain measurements untilobtaining the optimal solution for each specific target.

Reference is now made to FIG. 1, which is a schematic illustrationshowing principles of stimulation for central base coils, in accordancewith embodiments of the present invention. In the embodiment shown inFIG. 1, a schematic illustration of a base coil depicts the elements ofa central base coil in accordance with embodiments of the presentinvention, but does not depict the actual appearance of these elements.As shown in FIG. 1, central base coil 10 includes a base portion 12 anda return portion 32. A central axis 14 defines a mid-portion of coil 10.It should be readily apparent that central axis 14 may be an imaginaryaxis and may be straight or curved, and is used herein for descriptivepurposes and for geometric orientation. Base portion 12 includes a baseportion right side 16 to the right of central axis 14 and a base portionleft side 18 to the left of central axis 14. Directions of right sideand left side are defined in accordance with anatomical definitions.Thus, in the illustration, base portion right side 16 is on the leftside of the figure and base portion left side 18 is on the right side ofthe figure. Base portion right side 16 includes multiple right sidestimulating elements 20, depicted in FIG. 1 with arrows to illustratethe direction of electrical flow. Right side stimulating elements 20 arespaced apart from one another by distances D1. Base portion left side 18includes multiple left side stimulating elements 22, depicted in FIG. 1with arrows to illustrate the direction of electrical flow. Thedirection of electrical stimulation of left side stimulating elements 22with respect to central axis 14 is substantially the same as thedirection of electrical stimulation of right side stimulating elements20. Left side stimulating elements 22 are spaced apart from one anotherby a distance D2.

Return portion 32 includes a return portion right side 36 and a returnportion left side 38. Return portion right side 36 includes multipleright side return elements 40, and return portion left side 38 includesmultiple left side return elements 42. Right side and left side returnelements 40 and 42 are depicted in FIG. 1 with arrows to illustrate thedirection of electrical flow. It should be readily apparent from FIG. 1that the direction of electrical flow for right side and left sidereturn elements 40 and 42 is opposite the direction of electrical flowfor right side and left side stimulating elements 20 and 22, taken withrespect to central axis 14. Right side return elements 40 are connectedto right side stimulating elements 20 and left side return elements 42are connected to left side stimulating elements 22 via connectingelements 44. Thus, in one embodiment, current flows through a right sidereturn element 20 in one direction, referred to as a stimulatingdirection, then through a connecting element 44 in a transversedirection which is transverse to the stimulating direction, andafterwards through a return element 40 in an opposite direction which isopposite the stimulating direction and is referred to as a returningdirection. In some embodiments, all or some of stimulating elements,connecting elements and return elements are comprised of a singlecontinuous piece of coil, wherein different portions of the single pieceof coil are designated as either stimulating, connecting or returnelements depending on their positions and directions of current flow.

Right side return elements 40 are spaced apart from one another by adistance D3. Left side return elements 42 are spaced apart from oneanother by a distance D4. Right side base portion 16 and right sidereturn portion 36 are spaced apart from one another by a distance D5.Left side base portion 18 and left side return portion 38 are spacedapart from one another by a distance D6. By having distances D5 and D6which are sufficiently large, it is possible to minimize effects ofreturn current on the stimulated area. In some embodiments, distances D5and D6 are in the range of 4 to 10 cm. In other embodiments distances D5and D6 are in the range of 6 to 8 cm. Distances D5 and D6 can be eitherthe same or different.

Reference is now made to FIGS. 2A-2F, which are schematic illustrationsof base portion 12 in accordance with embodiments of the presentinvention. In some embodiments, as shown in FIG. 2A, the same number ofright side stimulating elements 20 and left side stimulating elements 22are used. In other embodiments, as shown in FIG. 2B, right sidestimulating elements 20 may include a greater or lesser number ofstimulating elements than left side stimulating elements 22. In someembodiments, as shown in FIG. 2C, distances D1 between right sidestimulating elements 20 may be variable. In some embodiments, distancesD2 between left side stimulating elements 22 may be variable. DistancesD1 and/or D2 between stimulating elements may be uniform, variable orperiodic. In some embodiments, distances D1 may be variable whiledistances D2 may be uniform, as shown in FIG. 2C, or vice versa. In someembodiments, right side and/or left side stimulating elements 20, 22 mayinclude multiple groupings. As shown in FIG. 2D, multiple right sidegroupings 21 and/or multiple left side groupings 23 may be included.Distances D7, D8 between groupings may be uniform, variable or periodic.In some embodiments, as shown in FIG. 2E, multiple central axes 14 maybe included, wherein each of central axes 14 may be in a differentdirection and includes its own base portion 12 with right sidestimulating elements 20 and left side stimulating elements 22. In otherembodiments, as shown in FIG. 2F, right side stimulating elements 20 areat a vertical distance from left side stimulating elements 22 withrespect to central axis 14. It should be readily apparent that theembodiments shown herein are non-limiting examples of a base portion,and that other configurations may be included within the scope of theinvention as well.

Reference is now made to FIG. 3, which is an illustration of a returnportion 32, in accordance with embodiments of the present invention.Depicted in FIG. 3 is return portion right side 36, although it shouldbe readily apparent that return portion left side may have a similarconstruction. Right side return elements 40 are shown at two differentheights, wherein some of right side return elements 40 are configured tobe in contact with a body part. These right side return elements 40 arereferred to as contacting return elements 50. Some of right side returnelements 40 are configured to be protruding from the body part, and arereferred to as protruding return elements 52. Protruding return elements52 may be at a vertical distance or a horizontal distance from baseportion 12, as long as protruding return elements 52 are configured toprotrude from coil 10 such that they are configured not to contact thebody part which base portion 12 is configured to contact. Thus,connecting elements 44 may be horizontal connecting elements 46 or maybe vertical connecting elements 48 or may have additional configurationsas needed to connect return portion 32 to base portion 12.

In some embodiments, some of multiple right side return elements 40 arecontacting return elements 50 and some of multiple right side returnelements 40 are protruding return elements 52. In some embodiments, allof multiple right side return elements 40 are contacting return elements50. In some embodiments all of multiple right side return elements 40are protruding return elements 52. In some embodiments, some of multipleleft side return elements 42 are contacting return elements 50 and someof multiple left side return elements 42 are protruding return elements52. In some embodiments, all of multiple left side return elements 42are contacting return elements 50. In some embodiments all of multipleleft side return elements 42 are protruding return elements 52. Rightside return elements 40 and left side return elements 42 may be the sametype or different types from one another. For example, in someembodiments, all of right side return elements 40 are contacting returnelements 50 while some of multiple left side return elements 42 arecontacting return elements 50 and some of multiple left side returnelements are protruding return elements 52. In other embodiments, all ofright and left side return elements 40 and 42 are contacting returnelements 50. Any combination of protruding and/or contacting returnelements is possible and is included within the scope of the presentinvention.

Reference is now made to FIG. 4, which is an illustration of anatomicalsections of a head 100. For the purposes of illustrating the presentinvention, head 100 has four sections: a frontal section 102 at a frontportion of head 100, a parietal section 104 to the rear of frontalsection 102 and at a top portion of head 100, a temporal section 106 onthe side of head 100 and an occipital section 108 at a rear portion ofhead 100. Central base coil 10 is configured such that central axis 14may be positioned at a mid-point of head 100 with right side stimulatingelements on one side of head 100 and left side stimulating elements onanother side of head 100. In other embodiments, central axis 14 ispositioned at a different location of head 100, such as a temporalsection 106, and right and left side stimulating elements 20 and 22 mayalso be positioned on temporal section 106 or may be positioned atdifferent locations on head 100. Thus, for example, base portion 12 maybe positioned on frontal section 102, with central axis 14 running alongan anterior-posterior central line. In another embodiment, base portion12 may be positioned on temporal section 106, with central axis 14running along a posterior-anterior central line. In yet anotherembodiment, base portion 12 may be positioned on parietal section 104,with central axis 14 running along a posterior-anterior central line. Inyet another embodiment, base portion 12 may be positioned on frontalsection 102, with central axis 14 running along a lateral-medial line.In this way, base portion 12 stimulates a section of the brain on twoside of central axis 14, while return portion brings returning currentback at a section which is remote from the stimulated section of thebrain. In some embodiments, both base portion 12 and return portion 32are adjacent to the head, and in some embodiments, base portion 12 isadjacent to the head while return portion 32 is remote from the head. Insome embodiments base portion 12 is adjacent to the head while some ofreturn portion 32 elements are adjacent to the head and some of returnportion 32 elements are remote from the head. In some embodiments,connecting elements 44 are adjacent to the head and in otherembodiments, connecting elements 44 are remote from the head. Yet inother embodiments some of connecting elements 44 are adjacent to thehead and some of them are remote from the head. In some embodiments,multiple base portions 12 are used with multiple central axes, as willbe described further hereinbelow.

Reference is now made to FIG. 5, which is a perspective illustration ofa coil 110, which is an example of a central base coil 10 in accordancewith embodiments of the present invention. Coil 110 includes a baseportion 12 having a base portion right side 16 and a base portion leftside 18 on the two sides of central axis 14. Base portion right side 16and base portion left side 18 are substantially horizontal and parallelwith respect to central axis 14. Base portion 12 has four groupings: afirst right side grouping 21, a second right side grouping 25, a firstleft side grouping 23, and second left side grouping 27. First andsecond right side groupings 21 and 25 each have right side stimulatingelements 20, wherein in each of the first and second right sidegroupings 21 and 25, right side stimulating elements 20 are spacedrelatively close to one another, with a distance D1 (not shown in theperspective illustrations due to the relatively close spacing) betweenright side stimulating elements 20 approximately equal to 0.3 cm. Adistance D7 between first and second right side groupings 21 and 25 isapproximately 2 cm. First and second left side groupings 23 and 27 eachhave left side stimulating elements 22, wherein in each of first andsecond left side groupings 23 and 27, left side stimulating elements 22are spaced relatively close to one another, with a distance D2 betweenleft side stimulating elements 22 approximately equal to 0.3 cm. Adistance D8 between first and second left side groupings 23 and 27 isapproximately 2 cm.

Coil 110 further includes a return portion 32 including a return portionright side 36 and a return portion left side 38. Return portion rightside 36 includes right side return elements 40 which are contactingreturn elements 50 since they are configured to contact a skull whencoil 110 is in place. Return portion left side 38 includes left sidereturn elements 42 which are also contacting return elements 50.

The distance D5 between right base portion 21 and right return portion36 is approximately 5 cm. The distance D6 between left base portion 23and left return portion 38 is approximately 5 cm.

Coil 110 is configured to be placed on medial frontal cortex regionssuch as medial prefrontal cortex or medial motor cortex, and is used tostimulate medial brain regions such as the anterior cingulate cortex,and may be useful for treating, for example, blepharospasm or Tourette'ssyndrome.

Reference is now made to FIG. 6, which is a perspective illustration ofa coil 210, which is another example of a central base coil 10 inaccordance with embodiments of the present invention. Coil 210 includesa base portion 12 having a base portion right side 16 and a base portionleft side 18 on the two sides of central axis 14. Base portion rightside 16 and base portion left side 18 are partially vertical andpartially parallel with respect to central axis 14. Base portion rightside 16 includes multiple right side stimulating elements 20, which arespaced apart from one another by a distance D1 of approximately 0.3 cm.Base portion left side 18 includes multiple left side stimulatingelements 22, which are spaced apart from one another by a distance D2 ofapproximately 0.3 cm. Right side stimulating elements 20 and left sidestimulating elements 22 are configured such that when coil 210 is placedon the head, the stimulating elements 20 and 22 extend from a top of thehead over a portion of the forehead and/or temples. At a top portion ofcoil 210, base portion right side 16 and base portion left side 18 areadjacent to one another, and as the stimulating elements 20 and 22descend, base portion right side 16 and base portion left side 18 areangled away from each other, such that at the widest point, base portionright side 16 and base portion left side 18 are a distance D10 ofapproximately 2 cm from one another.

Coil 210 further includes a return portion 32 including a return portionright side 36 and a return portion left side 38. Return portion rightside 36 includes right side return elements 40 which are contactingreturn elements 50 since they are configured to contact a skull whencoil 210 is in place. Return portion left side 38 includes left sidereturn elements 42 which are also contacting return elements 50.Connecting elements 44 connect right side stimulating elements 20 toright side return elements 40 and connect left side stimulating elements22 to left side return elements 42. Right side stimulating elements 20,connecting elements 44 and right side return elements 40 formsubstantially a triangular shape, and left side stimulating elements 22,connecting elements 44 and left side return elements 42 formsubstantially a triangular shape, wherein the triangular shape on theleft side and the triangular shape on the right side are substantiallyin contact with one another at a top portion of coil 210.

Coil 210 is configured to be placed on medial frontal cortex regionssuch as medial prefrontal cortex and/or medial orbitofrontal cortex, andis used to stimulate orbitofrontal cortex regions including theparacingulate cortex, and may be useful for treating, for example,autism and Asperger's disease.

Reference is now made to FIG. 7, which is a perspective illustration ofa coil 310, which is another example of a central base coil 10 inaccordance with embodiments of the present invention. Coil 310 includesa base portion 12 having a base portion right side 16 and a base portionleft side 18 on the two sides of central axis 14. Base portion rightside 16 and base portion left side 18 are substantially horizontal andparallel to central axis 14. Base portion right side 16 includesmultiple right side stimulating elements 20, which are spaced apart fromone another by a distance D1 of approximately 0.3 cm. Base portion leftside 18 includes multiple left side stimulating elements 22, which arespaced apart from one another by a distance D2 of approximately 0.3 cm.Right side stimulating elements 20 and left side stimulating elements 22are configured such that when coil 310 is placed on the head, thestimulating elements 20 and 22 are in contact with the head. In oneembodiment, coil 310 is positioned on top of the head with bilateralsymmetry, such that stimulating elements 20 and 22 lie on top of medialhead regions. In another embodiment, coil 310 is positioned on a lateralhead region, such as a left or right prefrontal cortex, so thatstimulating elements 20 and 22 are adjacent to lateral head regions. Thedistance D10 between an innermost left side stimulating element 315 andan innermost right side stimulating element 317 (i.e., the distance D10between base portion left side 18 and base portion right side 16) isapproximately 4-5 cm, and in some embodiments, may be in a range of 0.5to 25 centimeters. In some embodiments, the range of distance D10 isbetween 2-6 centimeters or between 10-20 centimeters, for example. Itshould be readily apparent that the distance may be any reasonabledistance and is not limited to the distances listed herein.

Coil 310 further includes a return portion 32 including a return portionright side 36 and a return portion left side 38. Return portion rightside 36 includes right side return elements 40 which are contactingreturn elements 50 since they are configured to contact a skull whencoil 310 is in place. Return portion left side 38 includes left sidereturn elements 42 which are also contacting return elements 50.Connecting elements 44 connect right side stimulating elements 20 toright side return elements 40 and connect left side stimulating elements22 to left side return elements 42. In one embodiment, as shown in FIG.7, right side stimulating elements 20, connecting elements 44 and rightside return elements 40 form substantially a rectangular shape, and leftside stimulating elements 22, connecting elements 44 and left sidereturn elements 42 form substantially a rectangular shape, wherein therectangular shape on the left side and the rectangular shape on theright side are configured to lie on a top portion of a head. In otherembodiments, right side stimulating elements 20, connecting elements 44and right side return elements 40 form other shapes, such as asubstantially rectangular with angled corners, elliptical, circularshapes, or combinations thereof. Similarly, left side stimulatingelements 22, connecting elements 44 and left side return elements 42form other shapes, such as substantially rectangular with angledcorners, elliptical, circular shapes, or combinations thereof.

The distance D5 between base portion right side 16 and return portionright side 36 is approximately 5 cm. The distance D6 between baseportion left side 18 and return portion left side 38 is approximately 5cm.

Coil 310 is configured to be placed on medial frontal cortex regionssuch as medial prefrontal cortex or medial motor cortex, or on lateralprefrontal cortex, and is used to stimulate medial and/or lateralprefrontal cortex regions, medial and/or lateral motor cortex regions,and may be useful for treating, for example, multiple sclerosis.

Reference is now made to FIGS. 8A-8B, which are perspectiveillustrations of a coil 410, which is another example of a central basecoil 10 in accordance with embodiments of the present invention. Coil410 includes a base portion 12 having a base portion right side 16 and abase portion left side 18 on the two sides of central axis 14. Baseportion right side 16 and base portion left side 18 are substantiallyhorizontal and parallel to central axis 14. Base portion right side 16includes at least one right side grouping 21, with multiple simulatingelements 20. In some embodiments, as shown in FIG. 8A, base portionright side 16 includes two right side groupings 21 and 25, each of whichincludes multiple stimulating elements 20, which are spaced apart fromone another by a distance D1 of approximately 0.3 cm. Base portion leftside 18 includes at least one left side grouping 23, with multiplesimulating elements 22. In some embodiments, as shown in FIG. 8A, baseportion left side 18 includes two left side groupings 23 and 27, each ofwhich includes multiple left side stimulating elements 22, which arespaced apart from one another by a distance D2 of approximately 0.3 cm.Second right side grouping 23 and second left side grouping 27 areadjacent to one another on either side of central axis 14. Right sidestimulating elements 20 and left side stimulating elements 22 areconfigured such that when coil 410 is placed on the head, thestimulating elements 20 and 22 lie along a top of the head. The distanceD7 between right side groupings 21 and 25 is approximately 2 cm. Thedistance D8 between left side groupings 23 and 27 is approximately 2 cm.

In some embodiments, as shown in FIG. 8B, an innermost right sidestimulating element 415 is adjacent to an innermost left sidestimulating element 417 at central axis 14, and an outermost right sidestimulating element 419 is separated from an outermost left sidestimulating element 421 by a distance D11 of at least 3 centimeters, andin some embodiments by a distance of between 3 and 25 centimeters. Thus,the width of base portion 12 is between 3 and 25 centimeters in theembodiment shown herein, but may be other widths as well.

Coil 410 further includes a return portion 32 including a return portionright side 36 and a return portion left side 38. Return portion rightside 36 includes right side return elements 40 which are protrudingreturn elements 52 since they are configured to protrude from a skullwhen coil 410 is in place. Return portion left side 38 includes leftside return elements 42 which are also protruding return elements 52.Connecting elements 44 connect right side stimulating elements 20 toright side return elements 40 and connect left side stimulating elements22 to left side return elements 42. Right side stimulating elements 20,connecting elements 44 and right side return elements 40 formsubstantially a rectangular shape, and left side stimulating elements22, connecting elements 44 and left side return elements 42 formsubstantially a rectangular shape, wherein the rectangular shape on theleft side and the rectangular shape on the right side are configured tolie with base portion 12 lying on a top portion of a head and returnportion 14 protruding from the head.

The distance D5 between base portion right side 16 and return portionright side 36 is approximately 5 cm. The distance D6 between baseportion left side 18 and return portion left side 38 is approximately 5cm.

Coil 410 is configured to be placed on medial frontal cortex and/ormedial parietal cortex, and is used to stimulate the medial motorcortex, and may be useful for treating, for example, chronic pain or forrehabilitation of patients following stroke.

Reference is now made to FIG. 9, which is a perspective illustration ofa coil 510, which is another example of a central base coil 10 inaccordance with embodiments of the present invention. Coil 510 includesa base portion 12 having a base portion right side 16 and a base portionleft side 18 on the two sides of central axis 14. Base portion rightside 16 and base portion left side 18 are substantially horizontal withrespect to central axis 14. Base portion right side 16 includes multipleright side stimulating elements 20, which are spaced apart from oneanother by a distance D1 of approximately 0.3 cm. Base portion left side18 includes multiple left side stimulating elements 22, which are spacedapart from one another by a distance D2 of approximately 0.3 cm. Rightside stimulating elements 20 and left side stimulating elements 22 areconfigured such that when coil 510 is placed on the head, thestimulating elements 20 and 22 extend over a top of the head andslightly descend down the sides of the head such that base portion rightside 16 and base portion left side 18 are angled away from each other.The distance D10 between base portion left side 18 and base portionright side 16 is approximately 4-5 cm.

Coil 510 further includes a return portion 32 including a return portionright side 36 and a return portion left side 38. Return portion rightside 36 includes right side return elements 40 which are contactingreturn elements 50 since they are configured to contact a skull whencoil 510 is in place. Return portion left side 38 includes left sidereturn elements 42 which are also contacting return elements 50.Connecting elements 44 connect right side stimulating elements 20 toright side return elements 40 and connect left side stimulating elements22 to left side return elements 42. Right side stimulating elements 20,connecting elements 44 and right side return elements 40 formsubstantially a triangular shape, and left side stimulating elements 22,connecting elements 44 and left side return elements 42 formsubstantially a rectangular shape, wherein the rectangular shape on theleft side and the triangular shape on the right side are substantiallyin contact with one another at a top portion of coil 510.

The distance D5 between base portion right side 16 and return portionright side 36 is approximately 5 cm. The distance D6 between baseportion left side 18 and return portion left side 38 is approximately 5cm.

Coil 510 is configured to be placed on medial frontal cortex such asmedial prefrontal cortex or medial motor cortex, and is used tostimulate deep motor cortex regions at a depth of up to 3-5 cm, and maybe useful for treating, for example, chronic pain, stroke rehabilitationor any motor disorder.

Reference is now made to FIG. 10, which is a perspective illustration ofa coil 610, which is another example of a central base coil 10 inaccordance with embodiments of the present invention. Coil 610 includesa base portion 12 having a base portion right side 16 and a base portionleft side 18 on the two sides of central axis 14. Base portion rightside 16 and base portion left side 18 are substantially horizontal andparallel to central axis 14. Base portion right side 16 includesmultiple right side stimulating elements 20, which are spaced apart fromone another by a distance D1 of approximately 0.3 cm. Base portion leftside 18 includes multiple left side stimulating elements 22, which arespaced apart from one another by a distance D2 of approximately 0.3 cm.Right side stimulating elements 20 and left side stimulating elements 22are configured such that when coil 610 is placed on the head, thestimulating elements 20 and 22 lie along a top of the head. The distanceD10 between base portion left side 18 and base portion right side 16 isapproximately 4-5 cm.

Coil 610 further includes a return portion 32 including a return portionright side 36, and a return portion left side 38. Return portion rightside 36 includes right side return elements 40 which are contactingreturn elements 50 since they are configured to contact a skull whencoil 610 is in place. Return portion left side 38 includes left sidereturn elements 42 which are also contacting return elements 50.Connecting elements 44 connect right side stimulating elements 20 toright side return elements 40 and connect left side stimulating elements22 to left side return elements 42. Right side stimulating elements 20,connecting elements 44 and right side return elements 40 formsubstantially a rectangular shape, and left side stimulating elements22, connecting elements 44 and left side return elements 42 formsubstantially a rectangular shape, wherein the rectangular shape on theleft side and the rectangular shape on the right side are configured tolie on a top portion of a head.

The distance D5 between base portion right side 16 and return portionright side 36 is approximately 5 cm. The distance D6 between baseportion left side 18 and return portion left side 38 is approximately 5cm.

Coil 610 is configured to be placed on medial frontal cortex regionssuch as medial prefrontal cortex or medial motor cortex, and is used tostimulate motor cortex regions, and may be useful for treating, forexample, chronic pain, stroke rehabilitation, or any motor disorder.

Reference is now made to FIG. 11, which is a perspective illustration ofa coil 710, which is another example of a central base coil 10 inaccordance with embodiments of the present invention. Coil 710 is acombination coil, which is comprised of two separate coils positionedtogether within a single helmet. A central axis 14 separates the twocoils from one another. A first coil 710R, is positioned on a right sideof central axis 14 and a second coil 710L is positioned on a left sideof central axis 14. First coil 710R includes a first coil base portion12R having a first coil base portion right side 16R and a first coilbase portion left side 18R on the two sides of a first coil central axis14R. Second coil 710L includes a second coil base portion 12L having asecond coil base portion right side 16L and a second coil base portionleft side 18L on the two sides of a second coil central axis 14L. Firstcoil base portion right side 16R and first coil base portion left side18R are substantially horizontal and parallel to first coil central axis14R. Second coil base portion right side 16L and second coil baseportion left side 18L are substantially horizontal and parallel tosecond coil central axis 14L. First coil base portion right side 16Rincludes multiple first coil outer section stimulating elements 20R,which are spaced apart from one another by a distance D1 ofapproximately 0.3 cm. First coil base portion left side 18R includesmultiple first coil inner portion stimulating elements 22R, which arespaced apart from one another by a distance D2 of approximately 0.3 cm.Second coil base portion right side 16L includes multiple second coilinner portion stimulating elements 20L, which are spaced apart from oneanother by a distance D1 of approximately 0.3 cm. Second coil baseportion left side 18L includes multiple second coil outer portionstimulating elements 22L, which are spaced apart from one another by adistance D2 of approximately 0.3 cm. Coil 710 is configured such thatwhen placed on the head, the stimulating elements 20R, 20L, 22R and 22Llie along the sides of the head. The distance D10 between first coilbase portion left side 18R and first coil base portion right side 16R isapproximately 2 cm. The distance D11 between second coil base portionleft side 18L and second coil base portion right side 16L isapproximately 2 cm.

First coil 710R further includes a first coil return portion 32Rincluding a first coil return portion inner section 36R and a first coilreturn portion outer section 38R. First coil return portion innersection 36R includes first coil inner section return elements 40R, whichare protruding return elements 52 since they are configured to protrudevertically from a skull when coil 710 is in place. In some embodiments,first coil inner section return elements 40R are configured such that afirst return element is configured to contact a skull, a second returnelement is positioned directly above the first return element, and soon, until all of the first coil inner section return elements form avertically protruding column of return elements. First coil returnportion outer section 38R includes first coil outer section returnelements 42R, which are contacting return elements 50. Similarly, secondcoil 710L further includes a second coil return portion 32L including asecond coil return portion inner section 36L and a second coil returnportion outer section 38L. Second coil return portion inner section 36Lincludes second coil inner section return elements 40L, which areprotruding return elements 52 since they are configured to protrudevertically from a skull when coil 710 is in place. In some embodiments,second coil inner section return elements 40L are configured such that afirst return element is configured to contact a skull, a second returnelement is positioned directly above the first return element, and soon, until all of the first coil inner section return elements form avertically protruding column of return elements. Second coil returnportion outer section 38L includes second coil outer section returnelements 42L, which are contacting return elements 50. Connectingelements 44 connect first coil right side stimulating elements 20R tofirst coil inner section return elements 40R, connect first coil leftside stimulating elements 22R to first coil outer section returnelements 42R, connect second coil right side stimulating elements 20L tosecond coil inner section return elements 40L, and connect second coilleft side stimulating elements 22L to second coil outer section returnelements 42L. First coil right side stimulating elements 20R, connectingelements 44 and first coil inner section return elements 40R formsubstantially a rectangular shape, first coil left side stimulatingelements 22R, connecting elements 44 and first coil outer section returnelements 42R form substantially a rectangular shape, wherein therectangular shape on the left side and the rectangular shape on theright side of first coil 710R are configured to lie on a right side of ahead. Second coil right side stimulating elements 20L, connectingelements 44 and second coil inner section return elements 40L formsubstantially a rectangular shape, second coil left side stimulatingelements 22L, connecting elements 44 and second coil outer sectionreturn elements 42L form substantially a rectangular shape, wherein therectangular shape on the left side and the rectangular shape on theright side of second coil 710L are configured to lie on a left side of ahead.

The distance D5 a between first coil base portion right side 16R andfirst coil return portion outer section 38R is approximately 2.5 cm. Thedistance D5 b between first coil base portion left side 18R and firstcoil return portion inner section 36R is approximately 2.5 cm. Thedistance D9 a between second coil base portion right side 16L and secondcoil return portion inner section 36L is approximately 2.5 cm. Thedistance D9 b between second coil base portion left side 18L and secondcoil return portion outer section 38L is approximately 2.5 cm.

Coil 710 is configured to be placed on medial or lateral frontal cortexregions such as medial or lateral prefrontal cortex, and is used tostimulate prefrontal cortex regions, and may be useful for treating, forexample, multiple sclerosis, or attention deficit and hyperactivitydisorder (ADHD), or major depression.

Reference is now made to FIG. 12, which is a perspective illustration ofa coil 810, which is another example of a central base coil 10 inaccordance with embodiments of the present invention. Coil 810 includesa base portion 12 having a base portion right side 16 and a base portionleft side 18 on the two sides of central axis 14. Base portion rightside 16 and base portion left side 18 are substantially horizontal andparallel to central axis 14. Base portion right side 16 includesmultiple right side stimulating elements 20, which are spaced apart fromone another by a distance D1 of approximately 0.3 cm. Base portion leftside 18 includes multiple left side stimulating elements 22, which arespaced apart from one another by a distance D2 of approximately 0.3 cm.Right side stimulating elements 20 and left side stimulating elements 22are configured such that when coil 810 is placed on the head, thestimulating elements 20 and 22 lie along a top of a medial portion ofthe head. The distance D10 between base portion left side 18 and baseportion right side 16 is between 2 and 5 cm.

Coil 810 further includes a return portion 32 including a return portionright side 36 and a return portion left side 38. Return portion rightside 36 includes right side return elements 40 which are contactingreturn elements 50 since they are configured to contact a skull whencoil 810 is in place. Return portion left side 38 includes left sidereturn elements 42 which are also contacting return elements 50.Connecting elements 44 connect right side stimulating elements 20 toright side return elements 40 and connect left side stimulating elements22 to left side return elements 42. Connecting elements 44 and right andleft side return elements 40 and 42 are curved such that right sidestimulating elements 20, connecting elements 44 and right side returnelements 40 form substantially a circular shape, and left sidestimulating elements 22, connecting elements 44 and left side returnelements 42 form substantially a circular shape. Each of the circularshapes are configured to lie on a top and side portion of a head.

The distance D5 (not shown due to the angle of the figure) between baseportion right side 16 and return portion right side 36 is approximately5 cm. The distance D6 between base portion left side 18 and returnportion left side 38 is approximately 5 cm.

Coil 810 is configured to be placed on medial frontal cortex regionssuch as medial prefrontal cortex or medial motor cortex, and is used tostimulate the anterior cingulate cortex, and may be useful for treating,for example, mood disorders including major depressive disorder, drugaddiction or other types of addiction, obsessive-compulsive disorder(OCD), chronic pain, Tourette's syndrome, or blepharospasm.

Reference is now made to FIGS. 13A and 13B, which are perspectiveillustrations of a coil 910, showing details of coil 910 and positioningof coil 910 on a head, respectively. Coil 910 is another example of acentral base coil 10 in accordance with embodiments of the presentinvention. Coil 910 includes a base portion 12 having a base portionright side 16 and a base portion left side 18 on the two sides ofcentral axis 14. For this embodiment, central axis 14 runs in alateral/medial direction, such that when coil 910 is positioned on askull, base portion right side 16 lies in front of base portion leftside. Base portion right side 16 and base portion left side 18 aresubstantially horizontal and parallel to central axis 14 and are curvedto conform to a shape of the skull. Base portion right side 16 includesmultiple right side stimulating elements 20, which are spaced apart fromone another by a distance D1 of approximately 0.3 cm. Base portion leftside 18 includes multiple left side stimulating elements 22, which arespaced apart from one another by a distance D2 of approximately 0.3 cm.Right side stimulating elements 20 and left side stimulating elements 22are configured such that when coil 810 is placed on the head, thestimulating elements 20 and 22 lie along a top of a lateral/medialportion of the head. The distance D10 between base portion left side 18and base portion right side 16 is between 4 and 7 cm.

Coil 910 further includes a return portion 32 including a return portionright side 36 and a return portion left side 38. Return portion rightside 36 includes an upper right side return portion 39 and a lower rightside return portion 41. Upper right side return portion 39 and lowerright side return portion 41 are separated from one another by adistance D30 of 2-3 cm. Right side return elements 40 are contactingreturn elements 50 since they are configured to contact a skull whencoil 910 is in place. In the embodiment shown herein, right side returnelements 40 are configured to contact an anterior portion of the head(i.e., the forehead), and are at least partially curved to conform tothe anatomy of the anterior portion of the head. Return portion leftside 38 includes left side return elements 42 which are protrudingreturn elements 52, wherein left side return elements 42 protrude from aposterior portion of the skull. In the embodiment shown herein, leftside return elements 42 are substantially straight, although otherconfigurations are possible as well. Connecting elements 44 connectright side stimulating elements 20 to right side return elements 40 andconnect left side stimulating elements 22 to left side return elements42.

The distance D5 between base portion right side 16 and return portionright side 36 is approximately 10 cm. The distance D6 between baseportion left side 18 and return portion left side 38 is approximately 10cm.

Coil 910 is configured to be placed on medial frontal cortex or medialparietal cortex, and is used to stimulate the posterior cingulate cortexand other parietal cortex regions, and may be useful for treating, forexample, mild cognitive impairment (MCI) and Alzheimer's disease.

Reference is now made to FIG. 14, which is a perspective illustration ofa coil 1010, in accordance with yet additional embodiments of thepresent invention.

Coil 1010 includes a base portion 12 having a base portion right side 16and a base portion left side 18 on the two sides of central axis 14.Base portion right side 16 and base portion left side 18 aresubstantially horizontal and parallel to central axis 14. Base portionright side 16 includes multiple right side stimulating elements 20,which are spaced apart from one another by a distance D1 ofapproximately 0.3 cm. Base portion left side 18 includes multiple leftside stimulating elements 22, which are spaced apart from one another bya distance D2 of approximately 0.3 cm. Right side stimulating elements20 and left side stimulating elements 22 are configured such that whencoil 1010 is placed on the head, the stimulating elements 20 and 22 liealong a top of a medial portion of the head. The distance D10 betweenbase portion left side 18 and base portion right side 16 is between 4and 8 cm.

Coil 1010 further includes a return portion 32 including a returnportion right side 36 and a return portion left side 38. Return portionright side 36 includes right side return elements 40 which arecontacting return elements 50 since they are configured to contact askull when coil 1010 is in place. Return portion left side 38 includesleft side return elements 42 which are also contacting return elements50. Connecting elements 44 connect right side stimulating elements 20 toright side return elements 40 and connect left side stimulating elements22 to left side return elements 42. Connecting elements 44 and right andleft side return elements 40 and 42 are curved such that right sidestimulating elements 20, connecting elements 44 and right side returnelements 40 form substantially a circular shape, and left sidestimulating elements 22, connecting elements 44 and left side returnelements 42 form substantially a circular shape. Each of the circularshapes are configured to lie on a top and side portion of a head.

The distance D5 between base portion right side 16 and return portionright side 36 is approximately 6 cm. The distance D6 between baseportion left side 18 and return portion left side 38 is approximately 6cm.

Coil 1010 is configured to be placed on medial frontal cortex regionssuch as medial prefrontal cortex or medial motor cortex, and is used tostimulate the medial cortex regions including motor cortex regions, andmay be useful for treating, for example, chronic pain and rehabilitationfollowing stroke.

Reference is now made to FIG. 15, which is a perspective illustration ofa coil 1110, in accordance with additional embodiments of the presentinvention.

Coil 1110 includes a base portion 12 having a base portion right side 16and a base portion left side 18 on the two sides of central axis 14.Base portion right side 16 and base portion left side 18 aresubstantially curved with respect to central axis 14. Base portion rightside 16 includes multiple right side stimulating elements 20, which arespaced apart from one another by a distance D1 of approximately 0.3 cm.Base portion left side 18 includes multiple left side stimulatingelements 22, which are spaced apart from one another by a distance D2 ofapproximately 0.3 cm. In some embodiments, stimulating elements 22 aregrouped in pairs, wherein each pair of stimulating elements 22 is spacedapart from another pair of stimulating elements 22 by a distance D8 ofapproximately 1 cm. Right side stimulating elements 20 and left sidestimulating elements 22 are configured such that when coil 1110 isplaced on the head, the stimulating elements 20 and 22 lie along a topof a medial portion of the head. The distance D10 between base portionleft side 18 and base portion right side 16 is between 4 and 7 cm.

Coil 1110 further includes a return portion 32 including a returnportion right side 36 and a return portion left side 38. Return portionright side 36 includes right side return elements 40 which arecontacting return elements 50 since they are configured to contact askull when coil 1110 is in place. Return portion left side 38 includesleft side return elements 42 which are also contacting return elements50. Connecting elements 44 connect right side stimulating elements 20 toright side return elements 40 and connect left side stimulating elements22 to left side return elements 42. Connecting elements 44 and right andleft side return elements 40 and 42 are curved such that right sidestimulating elements 20, connecting elements 44 and right side returnelements 40 form substantially a circular shape, and left sidestimulating elements 22, connecting elements 44 and left side returnelements 42 form substantially a circular shape. Each of the circularshapes are configured to lie on a top and side portion of a head.

The distance D5 between base portion right side 16 and return portionright side 36 is approximately 6-7 cm. The distance D6 between baseportion left side 18 and return portion left side 38 is approximately6-7 cm.

Coil 1110 can be configured to be placed on frontal cortex regions suchas medial prefrontal cortex or lateral prefrontal cortex, and is used tostimulate medial or lateral cortex regions including unilateral right orleft prefrontal cortex regions, and may be useful for treating, forexample, attention deficit disorder (ADHD), depression, bipolar disorderand geriatric depression.

Reference is now made to FIG. 16, which is a perspective illustration ofa coil 1210, in accordance with embodiments of the present invention.

Coil 1210 includes a base portion 12 having a base portion right side 16and a base portion left side 18 on two sides of a central axis 14. Baseportion right side 16 includes right side stimulating elements 20. baseportion left side 18 includes left side stimulating elements 22, whereinright and left side stimulating elements 20 and 22 are substantiallyparallel and horizontal with respect to central axis 14. Coil 1210further includes a return portion 32 including a return portion rightside 36 and a return portion left side 38. Return portion right side 36includes multiple right side return elements 40, and return portion leftside 38 includes multiple left side return elements 42. Both right sideand left side return elements 40 and 42 are contacting return elements50. In the embodiment shown herein, base portion 12 is configured to bepositioned on a temporal section 106 of head 100, and return portionright side 36 is configured to be positioned above base portion 12,closer to a parietal section 104. Coil 1210 is composed of two circularshapes, with the central groups of both circular shapes—right and leftside stimulating elements 20 and 22—forming the base portion. Baseportion right side 16 and left side 18 have a distance D5 ofapproximately 3 cm between them.

Coil 1210 is used to stimulate parietal and temporal lobe brain regionson either right or left hemisphere including the fusiform face area(FFA) and the superior temporal sulcus (STS) and may be useful fortreating, for example, autism in children and adults.

Reference is now made to FIG. 17A, which is a perspective illustrationof a coil 1310, in accordance with additional embodiments of the presentinvention.

Coil 1310 is designed to be placed adjacent to right or left humantemple (ie, temporal section 106 of head 100), in order to activateneuronal structures in the right or left insula. Coil 1310 depicted inFIG. 17 is a right coil. A left coil is a mirror image of the right coildepicted in FIG. 17. Coil 1310 includes a first central axis 14A and asecond central axis 14B, wherein first and second central axes 14A and14B are substantially perpendicular to one another. In the embodimentshown herein, first central axis 14 is configured to be positioned alonga posterior-anterior direction, and second central axis 14 is configuredto be positioned along an inferior-superior axis. A first base portion12A is positioned substantially parallel to first central axis 14A.First base portion 12A includes a first base portion right side 16A anda first base portion left side 18A, wherein first base portion rightside 16A includes multiple first base portion right side stimulatingelements 20A, and first base portion left side 18A includes multiplefirst base portion left side stimulating elements 22A. A second baseportion 12B is positioned substantially parallel to second central axis14B. Second base portion 12B includes a second base portion right side16B and a second base portion left side 18B, wherein second base portionright side 16B includes multiple second base portion right sidestimulating elements 20B, and second base portion left side 18B includesmultiple second base portion left side stimulating elements 22B.

Coil 1310 further includes a first return portion 32A corresponding tofirst base portion 12A and a second return portion 32B corresponding tosecond base portion 12B. First return portion 32A includes a firstreturn portion right side 36A having first return portion right sidereturn elements 40A, and a first return portion left side 38A havingfirst return portion left side return elements 42A. Connecting elements44A connect stimulating elements to corresponding return elements. Thus,first base portion right side stimulating elements 20A, connectingelements 44A and first return portion right side return elements 40Aform a substantially rectangular shape, and first base portion left sidestimulating elements 22A, connecting elements 44A and first returnportion left side return elements 42A form a substantially rectangularshape, wherein each rectangular shape is on a side of first central axis14A. In the embodiment shown herein, the rectangular shape comprised ofright side base portion 16A and right side return portion 32A is belowfirst central axis 14A, and the rectangular shape comprised of left sidebase portion 18A and left side return portion 38A is above first centralaxis 14A.

Second return portion 32B includes a second return portion right side36B having second return portion right side return elements 40B, and asecond return portion left side 38B having second return portion leftside return elements 42B. Connecting elements 44B connect stimulatingelements to corresponding return elements. Thus, second base portionright side stimulating elements 20B, connecting elements 44B and secondreturn portion right side return elements 40B form a substantiallyrectangular shape, and second base portion left side stimulatingelements 22B, connecting elements 44B and second return portion leftside return elements 42B form a substantially rectangular shape, whereineach rectangular shape is on a side of second central axis 14B.

In the embodiment shown herein, the rectangular shape comprised of rightside base portion 16B and right side return portion 32B is on one sideof second central axis 14B, and is at a vertical distance from therectangular shape comprised of left side base portion 18B and left sidereturn portion 38B, which is on the other side of second central axis14B.

In the embodiment shown herein, second base portion right sidestimulating elements 20B are also connecting elements 44A connectingfirst base portion left side stimulating elements 22A to first baseportion left side return elements 42A. In addition, first base portionleft side stimulating elements 22A and first base portion left sidereturn elements 32A, are also connecting elements 44B connecting secondbase portion right side stimulating elements 20B to second returnportion right side return elements 40B.

Stimulating elements 20A, 20B, 22A and 22B are spaced apart from oneanother by a distance D1 of approximately 0.3 cm. First base portionright side 16A and first base portion left side 18A are separated fromone another by a distance D10 of approximately 4.5 cm. Second baseportion right side 16B and second base portion left side are separatedfrom one another by a distance D12 of approximately 4 cm.

A distance D5 between first base portion right side 16A and first returnportion right side 36A is approximately 5-6 cm. A distance D6 first baseportion left side 18A and second return portion left side 38A isapproximately 5-6 cm. A distance D7 between second base portion leftside 18B and second return portion left side 38B is approximately 7 cm.A distance D8 between second base portion right side 16B and secondreturn portion right side 36B is approximately 10 cm.

Reference is now made to FIGS. 17B and 17C, which are illustrationsshowing positioning of coil 1310 on a head 100, from a side view and arear view, respectively, in accordance with embodiments of the presentinvention. Second return portion left side 38A is configured to protrudeabove the medial frontal cortex of the head. First return portion rightside return elements 40A are protruding return elements 52, since theyare curved away from the head to minimize undesired side effects due tooveractivation of the jaw and cheek muscles. Second left side returnelements 42B are protruding elements 52 since they are remote from thehead and located frontal to the forebrain. Second left side returnelements 40B are contacting return elements 50 and are configured tocontact the head at parietal and temporal cortex regions.

Coil 1310 can be used to stimulate unilaterally regions in the right orleft insular cortex and entorhinal cortex, and may be useful fortreating, for example, obesity, anorexia nervosa, bulimia, other eatingdisorders, various types of addiction including smoking addiction, drugaddiction, alcoholism, and also for treating schizophrenic subjectssuffering from auditory hallucinations.

EXAMPLES

In order for the designs of the central base coils described above to beeffective, the designs must be efficient with respect to energyconsumption, coil heating rate, compact size and ease of operation, andmust guarantee that the motor threshold and stimulation intensity formost of the relevant population is within an acceptable range withrespect to available stimulators power outputs. In order to test theseparameters and the efficacy of each coil for the particular indication,the following experiments were carried out.

Reference is now made to FIG. 18, which is an illustration of electricfield distribution maps of coil 110 of FIG. 5. The field distributionproduced by coil 110 was measured in a human head phantom model. Theprobe was moved in three directions inside the phantom model using adisplacement system with 1 mm resolution, and the field distribution ofcoil 110 was measured in the whole head model volume in 1 cm resolution.Axial and coronal field maps were produced. The field maps weresuperimposed on anatomical T1-weighted MRI coronal slices, to show theinduced field in each anatomical brain region. The field maps are shownfor stimulator output set at 100% of leg threshold. The dark pixelsindicate field magnitude above the threshold for neuronal activation.The threshold was set to 100 V/m, which is within the accepted range ofthresholds required for motor activation. The intensity of stimulatorpower output used for drawing the maps representing the distribution ofthe electric field for each coil was set to the level required to obtain100% of the neural motor threshold, at a depth of 3 cm, according to theapproximate depth of leg motor cortex sites. It can be seen that whenplacing the base portion of the coil over the prefrontal cortex,supra-threshold field is induced bilaterally in medial prefrontalregions including the anterior cingulate.

Reference is now made to FIG. 19, which is an illustration of electricfield distribution maps of coil 210 of FIG. 6. The field distributionproduced by coil 210 was measured using the method described above withreference to FIG. 18. The field maps are shown for stimulator output setat 110% of hand motor threshold. It can be seen that when placing thebase portion of the coil over the prefrontal cortex, supra-thresholdfield is induced bilaterally in medial prefrontal and orbitofrontalregions including the paracingulate cortex.

Reference is now made to FIG. 20, which is an illustration of electricfield distribution maps of coil 310 of FIG. 7. The field distributionproduced by coil 310 was measured using the method described above withreference to FIG. 18. The field maps are shown for stimulator output setat 120% of hand motor threshold. It can be seen that when placing thebase portion of the coil over the prefrontal cortex, supra-thresholdfield is induced in lateral and medial prefrontal regions of eitherright or left hemisphere.

Reference is now made to FIG. 21, which is an illustration of electricfield distribution maps of coil 410 of FIG. 8. The field distributionproduced by coil 410 was measured using the method described above withreference to FIG. 18. The field maps are shown for stimulator output setat 100% of leg motor threshold. It can be seen that when placing thebase portion of the coil over the motor cortex, supra-threshold field isinduced bilaterally in lateral and medial motor cortex regions.

Reference is now made to FIG. 22, which is an illustration of electricfield distribution maps of coil 510 of FIG. 9. The field distributionproduced by coil 510 was measured using the method described above withreference to FIG. 18. The field maps are shown for stimulator output setat 100% of leg motor threshold. It can be seen that when placing thebase portion of the coil over the motor cortex, supra-threshold field isinduced bilaterally in lateral and medial motor cortex regions.

Reference is now made to FIG. 23, which is an illustration of electricfield distribution maps of coil 610 of FIG. 10. The field distributionproduced by coil 610 was measured using the method described above withreference to FIG. 18. The field maps are shown for stimulator output setat 100% of leg motor threshold. It can be seen that when placing thebase portion of the coil over the motor cortex, supra-threshold field isinduced bilaterally in lateral and medial motor cortex regions.

Reference is now made to FIG. 24, which is an illustration of electricfield distribution maps of coil 710 of FIG. 11. The field distributionproduced by coil 710 was measured using the method described above withreference to FIG. 18. The field maps are shown for stimulator output setat 120% of hand motor threshold. It can be seen that when placing thebase portion of the coil over the prefrontal cortex, supra-thresholdfield is induced in lateral and medial prefrontal regions of eitherright or left hemisphere.

Reference is now made to FIG. 25, which is an illustration of electricfield distribution maps of coil 810 of FIG. 12. The field distributionproduced by coil 810 was measured using the method described above withreference to FIG. 18. The field maps are shown for stimulator output setat 100% of leg motor threshold. It can be seen that when placing thebase portion of the coil over the prefrontal cortex, supra-thresholdfield is induced bilaterally in medial prefrontal regions including theanterior cingulate cortex. Coil 810 is being used in a clinical studytesting the safety and efficacy of this device in treating subjectssuffering from cocaine addiction, Tourette's syndrome, chronic pain andOCD. Interim results from the OCD study of 9 subjects suffering from OCDshowed that 40% subjects showed response (defined as at least 35%improvement in YBOCS questionnaire), while no improvement was found inthe placebo control group.

Reference is now made to FIG. 26, which is an illustration of electricfield distribution maps of coil 910 of FIGS. 13A and 13B. The fielddistribution produced by coil 910 was measured using the methoddescribed above with reference to FIG. 18. The field maps are shown forstimulator output set at 110% of leg motor threshold. It can be seenthat when placing the base portion of the coil over the parietal cortex,supra-threshold field is induced bilaterally in medial parietal regionsincluding the posterior cingulate cortex.

Reference is now made to FIG. 27, which is an illustration of electricfield distribution maps of coil 1010 of FIG. 14. The field distributionproduced by coil 1010 was measured using the method described above withreference to FIG. 18. The field maps are shown for stimulator output setat 100% of leg motor threshold. It can be seen that when placing thebase portion of the coil over the motor cortex, supra-threshold field isinduced bilaterally in medial and lateral motor cortex regions.

Reference is now made to FIG. 28, which is an illustration of electricfield distribution maps of coil 1110 of FIG. 15. The field distributionproduced by coil 1110 was measured using the method described above withreference to FIG. 18. The field maps are shown for stimulator output setat 120% of hand motor threshold. It can be seen that when placing thebase portion of the coil over the prefrontal cortex, supra-thresholdfield is induced in lateral and medial prefrontal regions of eitherright or left hemisphere.

Reference is now made to FIG. 29, which is an illustration of electricfield distribution maps of coil 1210 of FIG. 16. The field distributionproduced by coil 1210 was measured using the same method as for FIG. 18.The field maps are shown for stimulator output set at 120% of motorthreshold. It can be seen that when placing the coil over the rightparietal cortex, supra-threshold field is induced mainly at rightparietal and temporal regions including deeper regions.

Reference is now made to FIG. 30, which is an illustration of electricfield distribution maps of coil 1310 of FIG. 17A. The field distributionproduced by coil 1310 was measured using the method described above withreference to FIG. 18. The field maps are shown for stimulator output setat 120% of hand motor threshold. It can be seen that when placing thebase portion of the coil over the temporal cortex, supra-threshold fieldis induced in lateral prefrontal and temporal regions of the relevanthemisphere including insular and entorhinal cortex regions.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention, which are, for brevity, described in thecontext of a single embodiment, may also be provided separately or inany suitable sub-combination.

While certain features of the present invention have been illustratedand described herein, many modifications, substitutions, changes, andequivalents may occur to those of ordinary skill in the art. It is,therefore, to be understood that the appended claims are intended tocover all such modifications and changes as fall within the true spiritof the present invention.

What is claimed is:
 1. A coil for magnetic stimulation, the coilcomprising: a base portion including a central axis defining a baseportion right side and a base portion left side, wherein said baseportion right side is positioned on a right side of said central axisand said base portion left side is positioned on a left side of saidcentral axis, multiple right side stimulating elements, said right sidestimulating elements positioned in said base portion right side,including an innermost right side stimulating element which is closestto said central axis and an outermost right side stimulating elementwhich is furthest from said central axis, wherein said multiple rightside stimulating elements are configured to carry electrical current insubstantially a first direction, and multiple left side stimulatingelements, said left side stimulating elements positioned in said baseportion left side, including an innermost left side stimulating elementwhich is closest to said central axis and an outermost left sidestimulating element which is furthest from said central axis, whereinsaid multiple left side stimulating elements are configured to carryelectrical current in substantially said first direction, wherein saidoutermost right side stimulating element is at a distance of at least 3centimeters from said outermost left side stimulating element; and areturn portion including multiple right side return elements positionedon the right side of said central axis, wherein each of said right sidereturn elements corresponds to one of said multiple right sidestimulating elements and wherein each of said right side return elementsis positioned further away from said central axis than its correspondingright side stimulating element, and multiple left side return elementspositioned on the left side of said central axis, wherein each of saidleft side return elements corresponds to one of said multiple left sidestimulating elements and wherein each of said left side return elementsis positioned further away from said central axis than its correspondingleft side stimulating element, wherein said return portion is spaced adistance away from said base portion.
 2. The coil of claim 1, whereinsaid multiple right side stimulating elements includes a number ofelements which is equal to a number of said multiple left sidestimulating elements.
 3. The coil of claim 1, wherein said multipleright side stimulating elements are spaced apart from one another andwherein said multiple left side stimulating elements are spaced apartfrom one another.
 4. The coil of claim 3, wherein said multiple rightside stimulating elements are spaced variably from one another.
 5. Thecoil of claim 4, wherein said multiple right side stimulating elementsinclude multiple right side groupings of stimulating elements, andwherein said multiple right side groupings are spaced apart from oneanother.
 6. The coil of claim 5, wherein said multiple right sidegroupings are spaced variably from one another.
 7. The coil of claim 3,wherein said multiple left side stimulating elements are spaced variablyfrom one another.
 8. The coil of claim 7, wherein said multiple leftside stimulating elements include multiple left side groupings ofstimulating elements, and wherein said multiple left side groupings arespaced apart from one another.
 9. The coil of claim 8, wherein saidmultiple left side groupings are spaced variably from one another. 10.The coil of claim 1, wherein said multiple right side return elementsare spaced apart from one another and wherein said multiple left sidereturn elements are spaced apart from one another.
 11. A coil formagnetic stimulation, the coil comprising: a base portion including acentral axis defining a base portion right side and a base portion leftside, wherein said base portion right side is positioned on a right sideof said central axis and said base portion left side is positioned on aleft side of said central axis, multiple right side stimulatingelements, said right side stimulating elements positioned in said baseportion right side, including an innermost right side stimulatingelement which is closest to said central axis and an outermost rightside stimulating element which is furthest from said central axis,wherein said multiple right side stimulating elements are configured tocarry electrical current in substantially a first direction, andmultiple left side stimulating elements, said left side stimulatingelements positioned in said base portion left side, including aninnermost left side stimulating element which is closest to said centralaxis and an outermost left side stimulating element which is furthestfrom said central axis, wherein said multiple left side stimulatingelements are configured to carry electrical current in substantiallysaid first direction, wherein said innermost right side stimulatingelement is at a distance from said innermost left side stimulatingelement; and a return portion including multiple right side returnelements positioned on the right side of said central axis, wherein eachof said right side return elements corresponds to one of said multipleright side stimulating elements and wherein each of said right sidereturn elements is positioned further away from said central axis thanits corresponding right side stimulating element, and multiple left sidereturn elements positioned on the left side of said central axis,wherein each of said left side return elements corresponds to one ofsaid multiple left side stimulating elements and wherein each of saidleft side return elements is positioned further away from said centralaxis than its corresponding left side stimulating element, wherein saidreturn portion is spaced a distance away from said base portion.
 12. Thecoil of claim 11, wherein said multiple right side stimulating elementsincludes a number of elements which is equal to a number of saidmultiple left side stimulating elements.
 13. The coil of claim 11,wherein said multiple right side stimulating elements are spaced apartfrom one another and wherein said multiple left side stimulatingelements are spaced apart from one another.
 14. The coil of claim 11,wherein said distance between the innermost right side stimulatingelement and the innermost left side stimulating element is at least 0.5cm.
 15. The coil of claim 14, wherein said distance between theinnermost right side stimulating element and the innermost left sidestimulating element is between 0.5 and 25 centimeters.
 16. The coil ofclaim 11, wherein said distance between the innermost right sidestimulating element and the innermost left side stimulating element isat least 2 centimeters.
 17. The coil of claim 16, wherein said distancebetween the innermost right side stimulating element and the innermostleft side stimulating element is between 2 and 6 centimeters.
 18. Thecoil of claim 11, wherein said distance between the innermost right sidestimulating element and the innermost left side stimulating element isat least 10 centimeters.
 19. The coil of claim 18, wherein said distancebetween the innermost right side stimulating element and the innermostleft side stimulating element is between 10 and 20 centimeters.